Rotary impact tool



Sept. 26, 1939. J. DE MooY ROTARY IMPACT TOOL Filed oct, 28, 1937 ATTORN EY eiiicient. exhausting motive fluid into and from the stator Another object of this invention is to produce il through passages and 2l and ports 23. 'lo a reversible rotary motor including a Work-en- For purpose of illustration, the prime mover 10 aan@ ser. ze, i935 l 2,174,314

l UNITED STATES PATENT OFFICE ROTARY IMPACT TOGL John ne Mooy, shaker Heights, ohio, mimi t The Cleveland Pneumatic Tool Com Cleveland, Ohio, a corporation of Ohio Application October 28, 1937, Serial No. 171,468 5 Claims. (Cl. Ilm-30.5)

Thisinvention relates broadly to rotary mopassage- 25 controlled by a throttle valve 2|, tors, but more particularly to fluid actuated rewhich valve is slidable by a trigger 22. Detachversible rotary motors oi' the impact type. ably secured within the outer end of the passage One object of this invention is to produce a 20, there is conduit connection 23, while the i 5 rotary motor especially iitted for setting or reinner end of the passage 2li opens into a passage 5 moving nuts, bolts or the like, and constituting 24 leading to the valve i6, which valve is formed a simple assembly which is strong, durable and with al plurality of ports 25 for admitting and gaging mechanism for imparting continuous rounit above described is represented as a fluid tary motion to the work until the torque of the actuated vane-type reversible motor wherein the motor reaches a predetermined resistance, and direction of rotation may be controlled through thereafter for automatically imparting a rapid the valve I6, but it 'is to be understood that any succession of rotative impacts tothe work for other suitable prime mover maybe substituted l5 settlngor removing the work. for the one above described without departing Other objects and advantages more or less from the scope and spirit of this invention. ancillary to the foregoing and the manner in Referring now more particularly to the present which the various objects are' attained, reside ih invention, 29 represents a front housing having the specific construction and aggroupment of the laterally extending lugs 30 each apertured to ren elements peculiar to this structure, as will become ceive a bolt 3l by which the front and center apparent from a more complete examination of housings are rigidly secured to the upper this specication, in the claims of which there housing l5. y are assembled certain speciilc combinations of Mounted withinv the upper end of the front parts and specic constructions indicative oi the housing 29 and 'extending part way into the center scope andspirit of the invention. housing I0, there is a stationary bearing-plate 32 In the drawing:` accommodating a' ball-bearing 33 within which Fig. 1 is allongitudinal sectional view of a fluid is journaied the lower. shafted end of the rotor actuated reversible rotary motor embodying the I2; which rotor extends well intothe front housan invention. I ing 29 to form a spindle 34, which is also referred to Fig. 2 is an enlarged cross sectional view taken toy as a prime mover. To simplify the present in a plane indicated by line 2- 2 in Fig. 1. disclosure, the spindle 34 is'shown as an integral Fig. 3 is a view similar to. Fig. 2, but 'showing part of the rotor I2, but in practice it is preferparts in a different position. y Y ably an independent part rigidly connected to the 35 Fig, 4 is an enlarged cross sectional view taken rotor by means of keys, splines or the like. in a plane indicated by line 4-'4 in Fig. 1. Y Rotatably mounted within the ironthousing Fig. 5 is aperspective view of one of the pawls 29, there is a cup-shaped casing or driven toolincluded in the mechanism. head 35, which is closed at its upper end by a Referring to the drawing in which like symbols cover 36 bearing on the spindle 34 and having 40 designate corresponding parts throughout the a reduced portion 3l guided within a ball-bearing 4o several views, i0 represents the center housing of 38. The lower end of the head 35 is reduced to the motor accommodating a 'stator Il having roform a shank 39 iournaled withinabali-bearing tatable therein a rotor I2 carrying radially mov- -4| I located' within the lower end of the housing able blades or vanes I3, whichvanes are respon- 29. The Shank 33 has a Polyghal P01110!! 4| sive to the action of the motive uid admitted prtl'llding fIOm the hOllSing 29 to receive a 45 into the stator, in the manner hereinafter de Socket member 42, detachablymounted thereon scribed, for ee'cting the rotation of the rotor. against relative rotation 'and enggeable with the The upper end of the rotor l2 is journaled withwork, which work is represented by a bolt 43. inA a ball-bearing I4 adequately mounted within Internally, the shank 39 is accurately machined sofan upper housing I5 having'rotatable therein a to rotatably receive the extreme lower end 44 of .0 valve l5 for controlling the direction of rotation the Ispindle 34. of the rotor I2. The outer end of the upper hous- Formed on the internal wallof the cup-shaped ing i5 is preferably formed with a iiange i1 havhead 35, there are two diametrically opposed lugs ing secured thereto by cap screwi a handle I9. 45 and 46, each having two laterally inclined side which is provided with a motive iiuid conveying walls 41 and 48. Toward the upper end of the u 2 head 35, these two lugs are cut away to produce a short cylindrical counterbore 48 within which is rotatably molmted a cross pin 5l extending through the spindle 34 and carried thereby against relative rotation.

, Rotatably mounted within the cup-shaped head 35, in spaced relation with the internal wall thereof, there is a driving head 5I, which is laterally supported by two ball-bearings 52 and 53 mounted on the spindle 34. The driving head 5I is drivingly connected to the spindle 34 by a resilient connection including a sleeve 54 made of resilient material such as rubber, which sleeve is mounted on the spindle 34 against relative rotation. 'Ihis sleeve, which is polygonalin cross section, is closely fitted within a corresponding axial bore 55 extending throughthe head 5l, thereby preventing relative rotation between the sleeve and the driving head.

The driving head 5I is accurately machined to pivotally receive the shank 56 of four pawls or hammer-weights 51, 58, 58 and 58. 'Ihe pawls 51 and 53 are diametrically opposed to each other and are capable of operative engagement with the lugs 45 and 45 of the head 35 during the rotation of the rotor in one direction, while the pawls 58 and 50 are diametrically opposed to each other and capable of operative engagement with the lugs aforesaid during rotation of the rotor 34 in the other direction. Each pawl is constantly urged into engagement with the inner wall of the cup-shaped head 35 by a springpressed plunger 6I carried by' the driving head 5I, and is formed with a lug-engaging-wing 6,2 extending substantially the full length of the head 5|. Each pawl is also provided with a smaller wing 53 disposed at about 180 from the wing 62, and located within the cylindrical counterbore 49 of the casing 35. As shown in Fig. 2, the wings 53 are normally engaging the cross-pin 50 which is carried by the spindle 34.

In the operation of the motor, motive fluid is admitted into the passage 28 through thev connection 23, and if the throttle valve 2l is opened by the trigger 22, the motive fluid is admitted to Y the valve I6 through the passage 24. The valve IG may be positioned for admitting motive iluid into the stator il through either the ports 26 or 21, for causing the rotation of the rotor in one or the other direction. As shown in Fig. l, the valve I5 is positioned for admitting the motive fluid into the stator Il through the passage 28 and the ports 23 for effecting the rotation of the rotor in a counterclockwise direction in Fig. 2, which rotation is of course transmitted to the spindle 34, and therefrom to the driving .head 5I` through the resilient connection including the sleeve 54. In this instance, the pawls 51 and 5B, forced into operative engagement with the side walls 41 of the lugs 45 and 45, will transmit rotation to the head 35, which vrotation is transmuted to the bolt 4a by the socket member 42.

If the bolt 43 is formed with a lefthand thread,

' this constant rotation transmitted to the bolt will last until the bolt is initially set, or until it reaches a predetermined resistance to rotation which will resist further rotation of the head 35. When this takes place, the spindle 34 driven by the rotor I2 will rotate relative to the head 5| by deforming the rilient sleeve 54, causing the cross pin 5l carried by the spindle 34 and engaging the wing 63 of the pawls to rotate relative to the pawls by exerting pressure on the wing 53 of the pawls 51 and'l! for causing the pivotal or lateral movement of the pawls out of ensagement with the side walls 41 of the lugs 45 and 45 of the driven head. It will be understood that due to the system of levers including the pin 50 and the pawls 55, a very small movement of the spindle 34 relative to the head 5I is needed to cause complete disengagement of the wings 51 of the pawls 55 with the lugs 45 and 48. In other words, through this system of levers the rate of speed of the disengaging movement of the wings 51 is actually greater than the rate of speed of the movement of the spindle 34 relative to the head 5i. Immediately after the disengagement of the pawls, the rotative energy stored within the resilient sleeve 54 during the deflection of this sleeve, will cause the head 5I to momentarily rotate at a greater-rate of speed than that of the spindle 34 until the head 35 has again resumed its normal position relative to the spindle, or until the cross pin 50 is again positioned as shown in Fig. 2 relative to the pawls carried by the head 5I. The time element required for the cross pin 50 to move from the ,position shown in Fig. 3 to the position shown in Fig'. 2, is calculated to be less than that required for one half revolution of the spindle 34, causing the pawls to assume their extreme outward position as shown in Fig. 2 before reengaging the lugs 45 and 46 of the head 35. As the driving head 5I rotates relative to the head 35, the pawls 51 and 59 will come into sudden engagement with the side wall 41 of the lugs 45 and 45 respectively, for delivering a rotative impact to head 35, which impact is transmitted to the work 43 through the shank 33 and the socket member 42. 'I'his sudden reengagement of the pawls with the head 35, will again momentarily prevent the rotation of the driving head 5I, causing the deflection of the resilient sleeve 54 and the limited rotation of the spindle 34 and cross pin 58 relative to the head 5I, which relative rotation will again cause the cross pin 5i#- to move the pawls 51 and 58 out of engagement with the lugs and 45 in the manner above described.

During the rotation of the spindle 34 in a counterclockwise direction in Fig. 2, the pawls 58 and 88 will simply ride the lugs 45 and 45 Without interference.

When the valve i6 is positioned for admitting motive fluid into the stator H for eiecting the rotation of the rotor l2 in a clockwise direction in Fig. 2, the pawls 58 and 60 engaging the side walls 48 of the lugs 45 and 46, will transmit the rotation of the rotor to the head 35. When this head is submitted to a predetermined torque resistance, the resilient sleeve 54 will again allow the rotation of the spindle 34 and of the cross pin relative to the head 5i, causing the cross pin 50 to exert pressure on the wing 63 of the pawls 58 and 68 for eifecting the disengagement of the pawls. Subsequently, the cross pin 50 will again assume the position shown in Fig. 2, allowing the sudden reengagement of the pawls 58 and 58 with the side wall 48 of the lugs 48 and 45 for imparting a rotative impact to the head 35 and conseimparted to the work until the motor is subjected to a predetermined resistance to rotation. 'Ihere.

after the driving connection or clutch between the motor and the work engaging member or tool head 35, which clutch includes the hammeraimera weights or pawls carried by the driving head i and the lugs carried by the tool head 3l, will be released to enable relative rotation between the driving head 5| and the driven head 35. As

previously stated, the release of the driving connection or clutch is eiiected by the movement oi' the-cross pin 50 relative to the driving head 5|. This cross pin does not i'orm a part .oi' the driving connection, and is actually operable by virtue of the limited relative rotation between the prime mover or spindle 34 and the driving head l5, which relative rotation is responsive to a predetermined resistance to rotation oi.' the tool heador driven head 35. It will also be understood that after disengagement, the clutch or driving connection between the two heads 35 and 5I is automatically reengageable due to the constant pressure Iexerted on the pawls 51 to 50 in` clusive by the spring pressed plungers 6I.

Although the foregoing description is neces-` sarily oi' a detailed characten'in order to completely set iorth the invention, it is to be under- .stood that the speciiic terminology is not intended to be restrictive or coniining and it is to be further understood that various rearrangements of parts and modications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

l. In a -tool of the character described, the combination of two rotatable elements held against axial movement, clutch means drivingly connecting said elements capable of release to enable relative rotation between said elements, said clutch means being automatically reengageable after release, a prime mover, a driving connection between said prime mover and one of said elements enabling limited relative motion therebetween undercertain conditions oi operation, and means operable by virtue of said relative motion for effecting the release of said clutch means. 1

2. In a tool of the character described, the combination of two rotatable elements, pawls carried by one of said elements movable relative thereto intov driving engagement with the other element and capable of disengagement therewith to enable relative rotation between said elements, said pawls being automatically reengageable after disengagement, a prime mover, a driving connection between said -prime mover and one of said elements enabling limited relative motion vtherebetween under certain conditions of operacluding lugs on said driven element, a pawl carried by said driving element movable relative thereto into driving engagement with said lugs and capable of disengagement therewith to enable relative `rotation between said elements, a prime mover, a, driving connection between said prime mover and said driving element enabling limited relative rotation therebetween under ce`rtain conditions of operation, and means responsive to said relative rotation for effecting the disengagement aforesaid,

4. In a tool of the character described, the combination of a rotatable tool head, a lug extending longitudinally of said head, a rotatable driving member, a pawl pivotally carried by said member capable of lateral movement into and out of engagement with said lug for delivering a succession of rotative impacts to said head, said pawl being automatically reengageable with said lug after disengagement, a prime mover, a driving connection between said prime mover and driving member enabling limited relative rotation therebetween under certain conditions of operation, and 'means carried by -said prime mover responsive to said relative 'rotation for effecting the lateral mov`ement of said pawl out of engagement with said lug.

5. In a tool of the character described, the combination of two rotatable elements, clutch means drivingly connecting said elements capable of release to enable relative rotation between said elements, said clutch means being automatically reengageable after release, a prime mover, a driving connection between said prime mover and one of said elements enabling relative movement therebetween under certain conditions of operation, and a pin carried by said` prime mover engageable with said clutch means by virtue of said relative movement for eiecting said release.

JOHN DE MOOY. 

